Chicago landlords—this Arctic freeze rolling in can turn into a nightmare fast if you’re not prepared. Frozen pipes are one of the most expensive winter surprises, and they hit vacant properties the hardest. If you have empty units right now, make sure the heat is on and set no lower than 55 degrees. Even one cold night can freeze a pipe. Open cabinet doors under sinks so warm air can circulate, and let faucets drip slightly to keep water moving. Over the next few days, do a quick walk-through o